<template>
	<view>
		<view class = "scroll-view-container">
      <!-- 左侧滑动区域 -->
     <scroll-view class="left-scroll-view" scroll-y :style="{height: wh + 'px'}">
        <block v-for="(item, i) in cateList" :key="i">
           <view :class="['left-scroll-view-item',i === active ?'active':'']" @click="activeChanged(i)">{{item.cat_name}}</view>
         </block>
     </scroll-view>
      <!-- 右侧滑动区域 二级标题-->
      <scroll-view class="right-scroll-view" scroll-y :style="{height : wh+'px'}" >
        <view class = "cate-lv2" v-for="(item2,i2) in cateLevel2" :key = "i2">
          <view class = "cate-lv2-title">/ {{item2.cat_name}} /</view>
          <!-- 右侧滑动区域 三级 -->
          <view class = "cate-lv3-list" style= "display: flex;flex-wrap: wrap;">
            <!-- item项 -->
            <view calss = "cate-lv3-item" v-for="(item3,i3) in item2.children" :key="i3" style= "width: 33.33%;margin-bottom: 10px;display: flex;flex-direction: column;align-items: center;">
              <image :src="item3.cat_icon" style= "height: 60px;width: 60px;"></image>
              <text style= "font-size: 12px;">{{item3.cat_name}}</text>
            </view>
          </view>
        </view>
      </scroll-view>
    </view>
	</view>
</template>

<script>
	export default {
	    data() {
	      return {
          wh: 0,
          cateList: [],
          active: 0,
          cateLevel2:[],
	      };
	    },
	    onLoad() {
	      // 获取当前系统的信息
	      const sysInfo = uni.getSystemInfoSync()
	      // 为 wh 窗口可用高度动态赋值
	      this.wh = sysInfo.windowHeight
        this.getCateList()
	    },
      methods: {
        // 获取左侧滚动条数据(一级分类)
        async getCateList() {
          const { data: res } = await uni.$http.get('/api/public/v1/categories')
          if (res.meta.status !== 200) return uni.$showMsg() 
          this.cateList = res.message
          //获取右侧分类
          this.cateLevel2 = res.message[0].children
        },
        
        //改变active值，左侧活动条
        activeChanged(i){
          this.active = i
          //重新为二级分类赋值
          this.cateLevel2 = this.cateList[i].children
        },
        
      }
	}
</script>


<style lang="scss">
  .scroll-view-container{
    display: flex;
  
    .left-scroll-view{
      width: 120px;
      
      .left-scroll-view-item {
        background-color: #F7F7F7;
        line-height: 60px;
        text-align: center;
        font-size: 12px;
        // 激活项的样式
        &.active {
          background-color: #ffffff;
          position: relative;

        // 渲染激活项左侧的红色指示边线
          &::before {
            content: ' ';
            display: block;
            width: 3px;
            height: 30px;
            background-color: #c00000;
            position: absolute;
            left: 0;
            top: 50%;
            transform: translateY(-50%);
          }
        }
      }
    }
  }
  .cate-lv2-title {
    font-size: 12px;
    font-weight: bold;
    text-align: center;
    padding: 15px 0;
  }
  
    
      
    
  
</style>
